Synergistic lubricating effect for calcium phosphate modified calcium sulfonate grease with highly load bearing capacity

Calcium sulfonate complex grease exhibits different lubrication mechanisms due to its different combination of calcium carbonate soap and complex agents. In an effort to explore the synergistic lubricating effect of complex agents and find breakthroughs in the performance of calcium sulfonate grease, calcium phosphate modified calcium sulfonate grease was prepared and tested compared with borates. At high loads of 600 N, the introduction of P-containing complex improved load bearing capacity of calcium sulfonate grease. The advantage it exhibited in terms of lubrication was attributed to the synergistic effect of calcium carbonate and calcium phosphate in thickener under harsh condition. The synergistic films about 30 nm depth composed of iron oxide, calcium oxide and iron phosphate played a decisive role in lubrication.